PAL-Timing scheme for a overscan raster line or blanked screen, no sprites:
+---------------------------------------------------------------+
| 1 2 3 4 5 6 |
|123456789012345678901234567890123456789012345678901234567890123|Cycles
+---------[------(--------------------------------------)---]---+Borders
|3-4-5-6-7-rrrrr++++++++++++++++++++++++++++++++++++++++-N0-1-2-|Phi-1 VIC
| |Phi-2 VIC
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|Phi-2 CPU
+---------------------------------------------------------------+
'-' = idle bus cycle (reads from the last byte of the video bank)
'+' = idle bus cycle (just like '-', but reads from
video_bank_base_address + $39FF if ECM ($D011 Bit 6) is selected)
<num> = pointer fetch for sprite <num> ; r = memory refresh cycle
N = extra '-' cycles for NTSC added here
x = processor executes instructions (BA high, AEC high)